Bandwidth demands from various video-based and 5G applications are putting a significant strain on the current telecommunications infrastructure. Methods that provide high spectral efficiency will be critical for sustaining the high data rates needed by future networks. This can be achieved in part by a dual-polarization transmission system using higher-order modulation for symbols. In a dual-polarized system, two data streams are transmitted at the same carrier frequency by two polarizations, i.e., the horizontal (H) and the vertical (V) polarization. In theory, the two polarizations are orthogonal to each other, which offers a doubling of the data rate compared to single-polarized transmission. In practice, the polarizations may not be perfectly orthogonal, which may lead to energy leakage from one stream to another and cause cross-polarization interference. Since the receivers for each of the polarizations are synchronized to the corresponding transmitter the interference from the other polarization may appear at the receiver for the other polarization with a certain frequency offset distortions that arises due to imperfections in the transmitter and receiver local oscillators (LOs) leading to additional phase noise. Furthermore, adopting higher-order modulation may render the communication system more sensitive to phase noise (PN). Thus, it would be of value in the industry to mitigate cross-polarization interference and phase noise distortion, while developing still further ways of increasing the spectral efficiency.